Article-wrapping machine



March 11, 1969 Y. c. vARGAs v ARTICLE-WRAPPING MACHINE Filed April 27.1965 7 of 2 5 v Sheet' I m INVENTOR XsMA/L 6' M42 ems 7'702/VEY March11, 1969 Y. c. VARGAS 3,431,701

ARTICLE-WRAPPING MACHINE Filed April 27. 1965 Sheet 2 of 2 INVENTOR.Yum/4 6'. 7424/45 BYWMWQA? fir rae/vs y United States Patent 8 ClaimsABSTRACT OF THE DISCLOSURE The apparatus relates to wrapping items suchas stacks of tortillas, in which an endless conveyor belt carries aplurality of rotatably mounted food stuffs supporting cups which areautomatically caused to rotate as the particular cup passes through awrapping housing located on the frame of the apparatus. A supply ofwrapping material having a free end extending over said belt and cups ispositioned to receive a stack of tortillas on each cup. Knives sever thewrapping material between each adjacent cup, and there is provided inthe wrapping housing a frustro-conical upper portion with an in-turnedlip which causes the wrapping material to be wrapped around the stack oftortillas as the cup is being rotated. The wrapped package is thensmoothed, flattened and heat sealed.

This invention relates to food packaging equipment, and particularly tomeans for wrapping and sealing uniform quantities of prepared foodstuffs such as tortillas.

It is now well known that food stuffs may be packaged in clearthermoplastic or thermosetting materials of polyethylene and equivalenttypes such as those marketed under the registered trade name Saran wrapby the Dow Chemical Company and Pliofilm by the E. I. du Pont de NemoursCompany.

Such wrappings protect the merchandise from contamination by dirt andother foreign matter, and help to maintain its freshness by keeping outair and deleterious organisms which would tend to spoil it.

In the past, it has been general practice to utilize a separate sheet ofwrapping material for each unit package of food, and to wrap thematerial by hand in each such sheet and then seal the package.

This process is time consuming and expensive, and the use of hand laboraffords added opportunity for dirt and foreign matter to be included inthe package.

The present invention offers an improvement in the construction andarrangement of automatic packaging equipment which permits moreeconomical and speedier processing and produces a more attractivepackage.

Preferably, it is comprised of a work table having an endless conveyorbelt and a plurality of work stations at which successive steps in theassembly of the final product may be carried out. These steps combine toenclose the tortillas in wrappers formed from an endless sheet ofwrapping material. A label describing and identifying the product isenclosed during the wrapping process.

With the foregoing in mind, it is a major object of this invention toprovide packaging means for tortillas and the like, which means willautomatically wrap and seal depackaging device which requires a minimumof contact between the food and human attendants.

A still further object of this invention is to provide a food wrappingand packaging device of simple construction and minimum cost which willafford substantial economies in the manufacture of processed foods.

It is another object of this invention to provide for a continuoussupply of wrapping material to be applied to a succession of separatepackages.

These and other objects will be better understood by reference to thedetailed description hereafter and to the drawings, which are to beunderstood as exemplary of a preferred embodiment of the invention, butnot as limiting its scope. It will be obvious that the invention is notlimited to wrapping food stuffs, but may also be utilized in packagingother related substances.

In the drawings:

FIG. 1 is a schematic perspective view of a preferred form of theinvention;

FIG. 2 is a side view of the embodiment shown in FIG. 1, illustratingthe mode of operation;

FIG. 2a is an enlarged perspective view of the conveyor belt drumsprovided at the two ends of the apparatus;

FIG. 3 is a transverse sectional view, taken as indicated by the line3-3 in FIG. 2 to show details of the means for severing successive unitsof the wrapping material;

FIG. 4 is a sectional view, taken as indicated by line 44 of FIG. 3 toshow details of the driving means for the severing equipment shown inthat figure;

FIG. 5 is a sectional View, taken from the exit end of the enclosingtunnel as indicated by line 55 of FIG. 2, to show details of theoperation and construction of the wrapping mechanism;

FIG. 6 is a fragmentary top view, partially in section, taken asindicated by line 66 in FIG. 5 to show additional details ofconstruction of the means for wrapping a segment of the wrappingmaterial around the foodstuff;

FIG. 7 is a schematic view, taken as indicated by line 7-7 in FIG. 6 toshow the construction of the enclosing tunnel from the entrance end;

FIG. 8 is an enlarged fragmentary cross sectional view taken along byline 8-8 of FIG. 2 to show details of the sealing means; and

FIGURE 9 is a perspective view of a wrapped package of tortillas or thelike as delivered at the right hand end of FIGS. 1 and 2.

Referring now to the drawings for a more detailed explanation of theoperation of the invention, the device, generally indicated as 1, isshown as having an elongated frame 2 which may be of suitable height toaccommodate an attendant. A female operator is shown for reference asstanding at A.

At one end of the frame 2 there is rotatably mounted a belt drive drum 3which supports and drives a continuous belt conveyor, indicatedgenerally by the arrow 4, in a manner which will be described in moredetail below. At its other end, the belt 4 is supported by an idler drum5 so that the belt forms a horizontal support surface which moves thefoodstuffs through the wrapping process in the manner to be described.

Belt 4 is made up of a series of parallel slats 6 secured to a flexiblebacking 7. The slats 6 may be of a material such as wood or metal, whilethe backing 7 may be a woven fabric reinforced rubber, leather, or thelike (see FIG. 3).

As can best be seen in FIG. 2a, the drive drum 3 has a reduced centralposition 8 to provide clearance for a portion of the cup-rotatingmechanism described hereafter. The drum 3 is supported on stub shafts 9.The idler drum 5 is of the same shape.

In order to drive the belt 4 at a constant speed, there is located anelectric motor (not shown) within housing 10. Sprocket 11 on the shaftof the motor drives the drum 3 through chain 12 engaging sprocket 13 onshaft 9.

Also located in housing is a label dispensing device which is actuatedby turning of sprocket 14. The dispensing device is conventional andtherefore is not shown. Suffice it to say that the device dispenses alabel as the sprocket 14 is turned a certain amount which is correlatedto the movement of the belt 4.

t regular intervals, the slats 6 are modified as at 15 to provide arecessed area to receive a cup 16 which supports the food stuffs for apurpose to be described. Centrally disposed in the recess area 15 thereis secured a journal bearing 17, which passes through backing 7 and isfixed thereto by a ferrule 18. Depending shaft portion 19 of cup isrotatably mounted in and through the journal bearing 17 and ferrule 18-.Each cup 20 is of the appropriate size to receive a stack of tortillasof the desired quantity with adequate marginal clearance for themanipulation of the wrapping material, as will be described below. Meansfor rotating cups 16 about the vertical axes of the vertical shaftportions 19 will be described later.

At the left end of the frame 2, as seen in FIGS. 1 and 2, is rotatablymounted a Wrapping supply roller 21 from which a continuous sheet ofwrapping material 22 is drawn over the endless slat array of belt 4.Material 22 is preferably formed of a transparent thermo-plastic, orthermosetting, substance. The material 22 is fed by the weight of thetortilla stacks pressing it against the moving belt 4. As wrappingmaterial 22 progresses to the right in FIGS. 1 and 2 under the influenceof the frictional engagement with belt 4, a series of labels 24 aredelivered at spaced intervals from the label slot 25. The label 24 isdelivered, with printed legend thereon face down, onto the wrappingmaterial 22 at each position of a cup 16.

An attendant, stationed as shown in FIG. 2, places a stack of tortillas26 on the wrapping material directly over each label, and therefore cup16. The weight of the tortillas so delivered presses the wrappingmaterial 22 against the conveyor belt 4 causing the material to be fedin direct proportion to movement of the belt.

The amount of material which will be used to enclose each tortilla stackis determined directly by a cut-off mechanism, indicated generally byarrow 28, located adjacent the transverse plane indicated by line 33 inFIG. 2. The mechanism 28 is seen to best advantage in the transversesectional view of FIG. 3 and sectional view of FIG. 4. The cut-offmechanism 28 is enclosed in a housing 29 extending transversely of theframe 2 and supporting a cut-off motor 30, located directly behind thecut-off driving gear 31 (as seen at the left in FIG. 3). The cut-offmotor 30 drives an endless chain 32 engaged with the driving gear 31 anda cut-off idler gear 34. Chain 32 has fixed thereto a number, here shownas two, of projecting slicing knife blades 35. Blades 35 are ofsufiicient length to project downwardly from the housing 28 and extendbetween the slats 6 of the endless belt 4, but must not come in contactwith the backing portion 7 thereof. This arrangement permits theseverance of the wrapping material 22 from one side of the endless belt4 to the other rapidly and cleanly. The housing 28 is positioned soclose to the belt 11 that it would be impossible for the operator to gether fingers in a position of peril from the cut-off knife blades 35.

The cut-off motor 30 is arranged to operate continuously while theapparatus 1 is operating, but the cut-off chain 32 and knife blades 35are required to function only intermittently. Hence, a clutch mechanismis employed to connect the motor 30 to the cut-off chain drive gear 31only at the precise time required to sever successive wrapping sheetsections 22, 22", and 22", from the continuous web 22. Obviously theblades 35 must be traversed rapidly to avoid interference i h SUCGGSSiVeones of the continuously moving slats 6. Therefore, the motor 30 must bedriven at a substantial speed, and the clutch connecting it to thecut-off drive chain 32 must operate rapidly.

The details of this clutch mechanism are illustrated in FIG. 4, wherethe continuously rotating motor 30 is shown secured to the back wall ofthe housing 29, with its drive shaft 36 extending through the housingWall. Fastening means such as bolt and nut members 37 are usedconventionally to secure the motor 30 to the housing wall. Within thehousing 29, the motor shaft 36 has fixed thereto, as by key means 39 andset screw 40, a clutch member 41 provided with a friction-resistantfacing 42.

It should be noted that drive gear 31 is journaled on shaft 36 so as topermit the motor 30 to run continuously although the gear 31 is notturning.

Housing 29 carries, on the side 44 thereof opposite that to whichcut-off motor 30 is secured, a strong electromagnetic repelling member45. Repelling member 45 operates through an extending shaft 46 carryinga yoke 4'7. The yoke 47 is fixed to carrier 49 of a ball bearing 50.Inner race 500 is pressed onto hub 51 of the cut-off drive gear 31.Hence when magnetic repulsion member 45 is energized, pressure istransmitted through yoke 47 and carrier 49, race 50a, bearing balls 50b,and race 500 of bearing 50 to force cut-off drive gear 31 into drivingengagement with the clutch facing 42 of the hub member 41. As motor 30is operating continuously the pick-up is extremely rapid and thesevering of the continuous strip 22 of Wrapping material is accomplishedwith such speed that it is unnecessary to interrupt the forward movementof the endless belt 4.

A preferred'method of activating the cut-off mechanism 28 will now bedescribed. As can be seen, there are evenly spaced holes '52 in the belt4. In the illustrated embodiment each hole 52 is adjacent a recess 15.At the station where the attendant is placing the tortilla stacks on thebelt 4, there is located a photoelectric switch 53. This type of switchis conventional and therefore will not be described further. It has thecapability that each time the cell is subjected to light, the circuit isclosed. In the present machine, each time a hole 52 passes the cell ofswitch 53, the current is closed and the solenoid 45 is energized.

The length of time and therefore distance, that the knife blade 35 movescan best be controlled by a timing device. However, it can also becontrolled by correlating the size of the holes 52 to the speed of thebelt 4. In the latter case, the solenoid would be energized during thetime that it takes 'for a hole '52 to be moved past the photoelectriccell. Naturally, other means can be used for activating the blades 35 inresponse to the movement of the cups 16 past the cut-off station.

Thus, successively severed sections 22, 22", and 22' are carried fromthe cut-0E mechanism 28 to the wrapping station housing 55. Each severedsection will carry a label 24, as delivered from the label slot 25, anda stack of 26 tortillas superimposed theron prior to passing under thecut-off housing 29. As the loaded and severed sheets approach thewrapping station housing 55, which is secured to the frame 2 by clampmeans 56, the leading portions 57 of each severed wrapping sheet 22',etc., will engage pick-up lips 59 which extend down toward the belt 4,just clearing the slats 6. As the successive sheet sections, 22', etc.,leave the cut-off housing 29, the longitudinal tension imparted by thefrictional drive is removed, and the sheets will pucker somewhat, asshown in FIG. 1. This makes it easy for the pick-up lips 59 to guide thewrapping sheets into the entrance end of the wrapping station housing55, as seen in FIG. 7.

The wrapping station housing 55 has a frustro-conical top portion 60with the in-turned lips 59 formed at the lower portion thereof. Thein-turned pick-up lips 59 are placed very close to the endless belt 4 atthe entrance end '58 to wrapping station housing 55-. The spacing fromthe belt increases as the distance from the entrance end of the housing55 increases, and the pick-up lips merge into converging. forming guides61 which terminate substantially horizontally at the discharge end 62.

As each cup :16 is moved through the housing 55, the cup and wrappersection on which the stack 26 of tortillas has been placed is rotatedabout a vertical axis. This is accomplished by the engagement of aresilient friction roller member '63, fixed on the lower end of theshaft portion 19 of the package-carrying cup 16, with a driving rail 64.The latter is secured to the frame 2 by bracket means 65. As the belt 4progresses along frame 2, the roller member 6-3 rotates the cup 16-, andsimultaneously the wrapping material sheet 22 is twisted and constrictedby the forming guides '61 so that it is tightly closed over the tortillastack 26.

On leaving the discharge end '62 of the housing 55, the wrapped stackpasses under a glass plate 66 which accomplishes a smoothing andflattening action on the wrapping, and permits visual inspection by theattendant.

The smoothed package then passes under a heated transverse roller 67which applies pressure and heat sufficient to accomplish the finalsealing of the package.

FIG. 8 shows how the roller '67 applies greater Pressure centrally ofthe wrapped package to insure proper closing and sealing of the Wrappingmaterial where the twisting has produced a thickened portion 69. The cup'16 is formed with a central boss 70 raised above the remainder of itsbottom. This projecting portion causes an increase in the unit pressuredeveloped in the central area over that developed at the periphery ofthe cup '16 when the heated roller 67 is encountered.

The cup 16 thereafter travels to the end of the forward progression ofthe endless belt 11, and over the idler drum 5 for return to the drivingdrum 3. As the cup 16 passes around the end, the sealed package 72 isdischarged by gravity onto a succeeding conveyor belt 7-4 or equivalentmeans for removing the packaged goods to a suitable storage area or tobe packed for shipment. It will be seen in FIG. 1 that the sealedpackage 72 is delivered to a subsequent work station, which may be aconveyor belt 74, with the label 24 upright and plainly visible.

It has been felt to be unnecessary to include electrical wiringdiagrams, since the circuitry is conventional and it is well within thescope of any qualified electrician to connect the electrical elementsdescribed.

It will be seen from the foregoing that there has here been presented animproved form of packaging equipment well adapted to produce a clean,sanitary and attractive package, the quality of the product beingvisibly apparent to a consumer or other lpurchaser.

I claim:

1. An article wrapping machine having a plurality of operating stationswhere sequential operations in the wrapping of articles with wrappingmaterial may take place, the machine comprising:

an elongated frame having two ends;

a plurality of spaced article carriers;

means on said frame for successively moving such carriers from a firstend toward a second end past a plurality of operation stations;

means for supplying a web of wrapping material at said one end on top ofat least one of said article carriers so that an article placed on topof the material and carrier will feed the material with the movement ofthe carrier, said material being supplied in a long strip;

cutter means on a frame operatively connected to the movement of acarrier so as to sever said material crosswise to the length of thestrip between each of said carriers;

folding means on said frame located at an operation station andoperating with the movement of each carrier as the same passes thatstation to fold the wrapping material around the article enclosing thesame;

and sealing means on said frame for sealing the material to hold it inthe position caused to be assumed by said folding means.

2. In a machine for packing articles,

means for supplying a web of wrapping material of predetermined widthpast a first operating station on said machine and a second operatingstation on said machine;

means located above said material at said first operating station forsuccessively depositing labels on said material at spaced positionsthereon;

said machine adapted at said second operating station to receive on topof said web of material for the purpose of being wrapped successivestacks of circular tortillas of a diameter substantially less than onehalf of the width of said web of material;

transport means to move said stacks from said second station past afifth station;

cutting means located at a third operations station on said machine,said cutting means being operatively connected to the movement of saidtransport means to1 sever the web between successive stacks of tortilas;

folding means located at a fourth operation station on said machine forfolding said material up around the side of the stack in contact withthe side of the stack and over the top of the stack as each stack ismoved past said fourth station, said folding means including means onsaid transport means for successively rotating said tortilla stacksabout a vertical axis during said folding operation;

and sealing means at a fifth operation station on said machine forsealingsaid material in the folded condition as each stack is moved pastthe fifth operation station.

3. In a device for packaging articles:

a frame;

transport means for transporting along said frame spaced stacks oftortillas and wrapping material received thereon;

means for supplying a web of wrapping material, said means being locatedadjacent a first operation station on the machine where stacks oftortillas are received on the web of the wrapping material;

said web of material resting on the transport means at said firstoperation station whereby the Weight of a stack of tortillas engages thematerial against the transport means, and the movement of the engagedportion of the transport means feeds the material away from the supplyroll toward a second opeartion station;

and cutting means located at second operation station on said machinefor severing said web of wrapping material between each stack oftortillas as the stacks are successively moved past the second operationstation;

actuator means operatively connecting said cutting means for actuatingsaid cutting means in response to light being received into a portion ofsaid actuator means;

and means on said transport means for blocking light from said portionof said actuator means except when said cutter means is at a point onsaid web between two adjacent stacks of tortillas.

4. In combination, in an article wrapping machine:

an elongated frame having two ends;

an endless belt supported 'by said frame;

means for driving said belt continuously over said frame;

means for supplying a continuous sheet of wrapping material at one endof said frame;

means for supplying labels at spaced intervals to said wrappingmaterial;

a work station on said machine where a predetermined quantity ofarticles to be wrapped is placed on top of each label passing the Workstation, the weight of the quantity of articles pressing the wrappingmaterial against said belt;

transverse severing means on said frame for severing said web ofwrapping material;

switch means for actuating said severing means at such time in relationto the movement of the belt that said severing means severs the webbetween the labels, said switch means being responsive to the movementof said belt;

means for bending upwardly and forcing together the outer edges of asevered portion of said wrapping material while simultaneously rotatingsaid material to form an enclosure over and around said material to bewrapped;

means for smoothing and flattening said rotated materials;

and means for subjecting said smoothed and flattened material to heatand pressure to seal the wrapping material about the enclosed materialin a separate package.

5. In combination, in an article wrapping machine having an elongatedframe with two ends, means for supplying a continuous strip of wrappingmaterial thereover:

means for carrying a plurality of article-receiving cups at spacedpositions on said belt;

said machine having a work station where a predetermined quantity ofarticles are placed on each of said cups as the cup passes said workstation;

transverse severing means for severing a section of said material foreach of said cups;

means for folding over and constricting said wrapping material abouteach of said defined quantities of articles to be wrapped, includingmeans for inducing rotation of said cups about vertical axes 'Whilepassing certain positions along said frame;

means for flattening and smoothing said wrapping material after suchtwisting of said material about said articles to be wrapped;

means for heating and applying sealing pressure to said wrappingmaterial after such flattening and smoothing;

and means for discharging such wrapped and sealed packages in sequence.

6. In combination in an article wrapping machine:

a work table having an endless belt of bendable material and a pluralityof slats secured at spaced intervals thereto;

a plurality of cup members rotatably journaled in said belt at regularlyspaced intervals;

a shaft extending downwardly from each of said rotatable cup members andhaving a driving roller secured thereto;

a drive rail fixed to said frame and adapted to be frictionally engagedby said driving rollers to rotate said cups as the cups are moved by therail;

means for supplying an endless strip of wrapping material feeding fromone end of said table over said belt and said cup members;

means for applying a succession of labels onto said strip of wrappingmaterial in spaced positions overlying said cup members, said labelsbeing adapted to receive over each of them a desired quantity ofmaterial to be wrapped;

means operable transversely of said table for successively severing saidwrapping material at a position intermediate each pair of adjacent cupsto provide independent wrapping material sections;

a frusto-conical housing having a tapered opening on the lower portionthereof with pick-up lips adapted to engage under, and lift, outerportions of said successively severed sections of said wrappingmaterial;

means for rotating each of said cups, the wrapping sheet and thematerial carried thereon as said assembly is carried along said taperedopening;

means for applying smoothing pressure over said rotated wrapping sheet;

and means for applying sealing heat and pressure over said assemblywhile increasing pressure over the central portion thereof.

7. In an article wrapping machine:

an elongated frame having a plurality of work stations;

said device having a flexible conveyor belt extending along said frameand between said work stations;

an endless supply of wrapping material feeding over said conveyor belt;

means responsive to the placing of a desired quantity of material to bewrapped over a label at a loading station to initiate traverse of saidwrapping material with said conveyor belt and means for severingsuccessive wrapping sheets from said endless wrapping supply betweensuccessive label carrying portions thereof;

means for lifting the leading portions of said severe sheets and guidingthem upwardly while rotating them and constricting them to enclose saidmaterial to be wrapped;

means for smoothing and flattening said rotated and constricted sheetsover the material being enclosed thereby;

and means for sealing said flattened wrapped material by the applicationof heat and pressure.

8. A device for preparing foodstuffs or the like for sale,

comprising:

an elongated frame;

an endless conveyor belt disposed on said frame, said belt including abendable backing having fixed thereto a plurality of slat membersdisposed crosswise of the belt at regular intervals;

a pluarity of foodstuff supporting cups disposed at regular intervals onsaid belt, said cups each having a shaft extending through a journalbearing in said backing;

a resilient driving roller fixed to each said shaft and arranged to beengaged against a rotation-inducing rail secured to the frame;

means for traversing said belt along said frame;

a rotation-inducing rail extending from said frame to engage saiddriving roller as the latter is moved past the rail by the belt;

means on said frame for supplying an endless supply of wrapping materialhaving a free and extending feeding over said belt and cups, saidwrapping material being drawn along said conveyor \belt by the frictioninduced by the weight of said material to be packaged;

severing means for severing said wrapping material into sheets ofuniform size, said severing means comprising:

a housing mounted transversely over said conveyor belt;

an endless chain extending around a pair of sprockets disposed withinsaid housing at right angles to the length of said frame;

a plurality of severing knives mounted on said chain and, duringmovement, extending below said housing sufficiently to pass betweenadjacent ones of said conveyor belt slats but not enough to touch saidbacking;

a severing motor mounted on said housing and rotating continuouslyduring operation of said belt;

and magnetically operated clutch means responsive to movement of saidbelt for intermittently connecting one of said sprockets to saidsevering motor, whereby said severing motor will drive said knivesrapidly across said conveyor belt 9 10 and wrapping material to sever asection of said and means for applying sealing heat and pressure towrapping material; said smoothed and flattened wrapping material. meanson one of said respective cup and the conveyor belt around said cuplocated above the elevation of References Cited the center portion ofthe cup for lifting the forward portions of each successively severedsection of 5 UNITED STATES PATENTS wrapping material when a foodstuff isresting on the 980,329 1/1911 Northrup 53-209 cup and the wrappingmaterial at that area is free of 2,653,430 9/1953 V g 53224 X tension;2,859,573 11/1958 Shelton 53l79 X a wrapping housing located on saidframe displaced 10 2,906,069 9/1959 Page et al. 532.09 X from thesevering means in the direction of travel 3,053,026 9/ 1962 Chapin etal. 53-179 of the belt, said housing having a frusto-conical 3,097,4647/1963 Re 53 209 pp portion and int-turned p defining the 1OWer3,135,078 6/1964 Keene et al. 53-32 X portion thereof, saidfrusto-conical portion decreas- 3,260,030 7/ 1966 Wach fit a1 34 ing indiameter as the distance from the severing 15 2,865,154 12/1958 coynemeans increases, said housing being disposed so that said lifted sheetportions are guided and compressed TRAVIS MCGEHEE, Primary Examiner bysaid lips over the foodstuffs to be wrapped while being traversed onsaid belt and simultaneously NEIL ABRAMsAsslsmn-t Exammer' rotated withsaid cup by the co-action of said rail 20 and said driving roller; menasfor smoothing and flattening said rotated and 53-389; 83355 compressedwrapping;

